1. Field of the Invention
The present invention relates to a linear vibrator, and more particularly, to a linear vibrator mounted in a mobile electronic device and applied to an apparatus for generating a soundless reception signal.
2. Description of the Related Art
In recent years, personal mobile terminals having large LCD screens have increased for the sake of user convenience. Accordingly, a touch screen method is adopted therein, and a vibration motor is used to generate vibrations when the touch screen is touched.
The vibration motor is an element that converts electrical energy into mechanical vibrations using the principle of generating electromagnetic force, and is mounted in a personal mobile terminal and used to inform a user of a soundless reception signal.
A vibration motor according to the related art generates mechanical vibrations by generating rotational force to rotate a rotation unit of unbalanced mass, the rotational force undergoing a rectifying action through a contact point between a brush and a commutator, thereby generating mechanical vibrations.
However, in such a brush type configuration using a commutator, the brush may cause mechanical friction and electrical sparks when passing through a gap between segments of the commutator during rotation of the motor, and may generate foreign substances, thereby shortening a lifespan of the motor.
Also, it may take a great deal of time to reach a target amount of vibrations, due to rotational inertia when voltage is applied to the motor, and thus, there may be a limitation in realizing suitable touch screen vibrations.
In order to overcome these disadvantages of motor lifespan and response, and realize a vibrating function in the touch screen, a linear vibrator is commonly used.
A linear vibrator does not use the rotating principle of the motor, and may periodically generate electromagnetic force through a spring installed in the linear vibrator and a mass body suspended from the spring according to a resonant frequency to cause resonance, thereby generating vibrations.
Such a linear vibrator needs to be slim and effectively manufactured according to current market trends toward miniaturization and slimness in mobile electronic devices. In addition, a linear vibrator should not affect the performance and characteristics thereof, even in a case in which several factors are involved.
However, a linear vibrator according to the related art may cause a change in the performance and characteristics thereof due to elements that vibrate therein, and as a result, may affect the performance of a mobile electronic device employing the linear vibrator.
Accordingly, there is an urgent demand for research into a linear vibrator that does not cause a change in the performance and characteristics thereof, even with elements vibrating therein.